Safety boundary
Use supplied kinetics datasets and approved simulations. No unsupervised reactive mixtures are required.
Explicit chemistry instruction
Initial-rate experiments compare trials near the start, before concentrations change substantially.
When one variable changes while others are held constant, the rate ratio can reveal how sensitive the reaction is to that variable.
This course treats rate-law exponents conceptually and quantitatively from supplied data rather than assuming them from coefficients.
Vocabulary: initial rate; controlled variable; rate ratio; concentration effect; empirical model.
Worked example
Doubling [A] while all else is fixed doubles initial rate in one dataset, supporting first-order dependence on A over that tested range.
Guided question
Trial 1 uses [A]=0.10 M with rate 0.020 M/s; Trial 2 uses [A]=0.20 M with rate 0.040 M/s. What relationship is supported?
Independent work
- Compare four initial-rate trials.
- Identify which variable changed.
- State one empirical concentration-rate relationship.
Misconception check
Reaction-order behavior comes from experimental rate data, not automatically from balanced-equation coefficients.
Formative check
What makes two initial-rate trials comparable?
Reveal response
Only one relevant variable changes while others are controlled.
Mentor evidence conference
Ask Archaemenes to audit graph slopes, units, controlled variables, and model limits.
Teacher guidance
Foundation: Use ratio tables.
Core: Infer simple empirical dependencies.
Extended: Compare competing rate models from multi-trial data.